| /* |
| * RTP parser for loss tolerant payload format for MP3 audio (RFC 5219) |
| * Copyright (c) 2015 Gilles Chanteperdrix <gch@xenomai.org> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavutil/attributes.h" |
| #include "libavutil/intreadwrite.h" |
| |
| #include "avio_internal.h" |
| #include "rtpdec_formats.h" |
| |
| struct PayloadContext { |
| unsigned adu_size; |
| unsigned cur_size; |
| uint32_t timestamp; |
| uint8_t *split_buf; |
| int split_pos, split_buf_size, split_pkts; |
| AVIOContext *fragment; |
| }; |
| |
| static void mpa_robust_close_context(PayloadContext *data) |
| { |
| ffio_free_dyn_buf(&data->fragment); |
| av_free(data->split_buf); |
| } |
| |
| static int mpa_robust_parse_rtp_header(AVFormatContext *ctx, |
| const uint8_t *buf, int len, |
| unsigned *adu_size, unsigned *cont) |
| { |
| unsigned header_size; |
| |
| if (len < 2) { |
| av_log(ctx, AV_LOG_ERROR, "Invalid %d bytes packet\n", len); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| *cont = !!(buf[0] & 0x80); |
| if (!(buf[0] & 0x40)) { |
| header_size = 1; |
| *adu_size = buf[0] & ~0xc0; |
| } else { |
| header_size = 2; |
| *adu_size = AV_RB16(buf) & ~0xc000; |
| } |
| |
| return header_size; |
| } |
| |
| static int mpa_robust_parse_packet(AVFormatContext *ctx, PayloadContext *data, |
| AVStream *st, AVPacket *pkt, |
| uint32_t *timestamp, const uint8_t *buf, |
| int len, uint16_t seq, int flags) |
| { |
| unsigned adu_size, continuation; |
| int err, header_size; |
| |
| if (!buf) { |
| buf = &data->split_buf[data->split_pos]; |
| len = data->split_buf_size - data->split_pos; |
| |
| header_size = mpa_robust_parse_rtp_header(ctx, buf, len, &adu_size, |
| &continuation); |
| if (header_size < 0) { |
| av_freep(&data->split_buf); |
| return header_size; |
| } |
| buf += header_size; |
| len -= header_size; |
| |
| if (continuation || adu_size > len) { |
| av_freep(&data->split_buf); |
| av_log(ctx, AV_LOG_ERROR, "Invalid frame\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if ((err = av_new_packet(pkt, adu_size)) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); |
| return err; |
| } |
| |
| pkt->stream_index = st->index; |
| memcpy(pkt->data, buf, adu_size); |
| |
| data->split_pos += header_size + adu_size; |
| |
| if (data->split_pos == data->split_buf_size) { |
| av_freep(&data->split_buf); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| |
| header_size = mpa_robust_parse_rtp_header(ctx, buf, len, &adu_size, |
| &continuation); |
| if (header_size < 0) |
| return header_size; |
| |
| buf += header_size; |
| len -= header_size; |
| |
| if (!continuation && adu_size <= len) { |
| /* One or more complete frames */ |
| |
| if ((err = av_new_packet(pkt, adu_size)) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); |
| return err; |
| } |
| |
| pkt->stream_index = st->index; |
| memcpy(pkt->data, buf, adu_size); |
| |
| buf += adu_size; |
| len -= adu_size; |
| if (len) { |
| data->split_buf_size = len; |
| data->split_buf = av_malloc(data->split_buf_size); |
| data->split_pos = 0; |
| if (!data->split_buf) { |
| av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); |
| av_packet_unref(pkt); |
| return AVERROR(ENOMEM); |
| } |
| memcpy(data->split_buf, buf, data->split_buf_size); |
| return 1; |
| } |
| return 0; |
| } else if (!continuation) { /* && adu_size > len */ |
| /* First fragment */ |
| ffio_free_dyn_buf(&data->fragment); |
| |
| data->adu_size = adu_size; |
| data->cur_size = len; |
| data->timestamp = *timestamp; |
| |
| err = avio_open_dyn_buf(&data->fragment); |
| if (err < 0) |
| return err; |
| |
| avio_write(data->fragment, buf, len); |
| return AVERROR(EAGAIN); |
| } |
| /* else continuation == 1 */ |
| |
| /* Fragment other than first */ |
| if (!data->fragment) { |
| av_log(ctx, AV_LOG_WARNING, |
| "Received packet without a start fragment; dropping.\n"); |
| return AVERROR(EAGAIN); |
| } |
| if (adu_size != data->adu_size || |
| data->timestamp != *timestamp) { |
| ffio_free_dyn_buf(&data->fragment); |
| av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| avio_write(data->fragment, buf, len); |
| data->cur_size += len; |
| |
| if (data->cur_size < data->adu_size) |
| return AVERROR(EAGAIN); |
| |
| err = ff_rtp_finalize_packet(pkt, &data->fragment, st->index); |
| if (err < 0) { |
| av_log(ctx, AV_LOG_ERROR, |
| "Error occurred when getting fragment buffer.\n"); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| const RTPDynamicProtocolHandler ff_mpeg_audio_robust_dynamic_handler = { |
| .enc_name = "mpa-robust", |
| .codec_type = AVMEDIA_TYPE_AUDIO, |
| .codec_id = AV_CODEC_ID_MP3ADU, |
| .need_parsing = AVSTREAM_PARSE_HEADERS, |
| .priv_data_size = sizeof(PayloadContext), |
| .close = mpa_robust_close_context, |
| .parse_packet = mpa_robust_parse_packet, |
| }; |